1. Field of the Invention
The invention relates to a shaft straightening and hardening machine, including a holder for a shaft-shaped workpiece. The holder can be moved circumferentially about an axis, which is essentially parallel to the axis of the workpiece, by a controlled rotary drive mechanism. The machine includes a coolant bath through which the holder passes as part of its path of circumferential or rotary movement. The holder includes at least one straightening shaft having a straightening mechanism or clement thereon, which is mounted at a specified location along the length of the workpiece and which acts radially upon the workpiece and can be swung sideways from said workpiece for the purpose of loading and unloading the workpiece.
2. Description of Related Art
In a prior art shaft straightening and hardening machine (as described in the prospectus from Hahn & Kolb, Stuttgart, No. 2510/24), a shaft-shaped workpiece may be clamped between two headstocks at a loading and unloading station. The machine includes several groups of straightening rolls, which can be moved along a bed parallel to the workpiece axis to specific locations along the length of the workpiece where the workpiece is to be acted upon with a specified or predetermined degree of straightening. To load and unload the workpiece into the machine, a straightening roll of each group of straightening rolls can be swung sideways or radially and the workpiece is loaded into, or unloaded from, the two headstocks. A rotary drive mechanism conveys the holder with the assigned straightening rolls through the coolant bath, usually an oil bath, for the purpose of workpiece quenching. After emerging from the oil bath, the hardened workpiece is removed from the headstocks after the straightening rolls have been swung out. The straightening rolls or rollers are substantially disc-shaped and results in relatively point by point straightening of the workpiece which can have an undesired negative impact on the workpiece, if the workpiece exhibits one or more axial, optionally also eccentric boreholes. The object of the present invention is to improve this type of machine.